My sister and I wore these, purchased from SHEIN. The pink one is 5Y and the blue one is 9-12M, but both were a bit small, so I think they're about 110 and 80 in Japanese sizes... We wore white T-shirts or long sleeves underneath. The fabric is thin, so they'll be for next year when it gets colder... Stored at home and already washed, so please refrain from purchasing if you are sensitive to such things.